AFR dropped at WOT
#1
AFR dropped at WOT
My AFR dropped to 10.2 in WOT last night. When I talked to STM a few months ago they said its okay to be around 10.6 which is the lowest it has ever gone until last night. I have had previous posts about power issues...could this be affecting my spark causing it to run rich? I have less then 500 miles on my plugs same as oil. I appreciate any advice on the situation...my evo is really fristrating me lately.
#2
EvoM Community Team Leader
Yah thats too low.... Do a boost leak test, that can cause afr to do that.
#4
EvoM Community Team Leader
Yah you will still be able to make boost, its just more work for the turbo and a loss in power. There are many guides on this site on how to do a boost leak test if you look for them.
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#10
EvoM Community Team Leader
You picking up any knock? Too many counts of knock will put you onto the low octane maps, which could be pretty rich. Also what are you LTFT low and LTFT mid?
#12
EvoM Community Team Leader
ltft stands for long term fuel trim. If it was your oxygen sensor, it would cause the ltft to be out of normal range. This is usually accompanied with a check engine light though. The rear 02 sensor is usually what is deleted. The front one is needed for scaling injectors, and closed loop operation.
#14
EvoM Community Team Leader
Without any scanning equipment it would be kinda hard to verify if the fuel trims are effecting your tune. You could do an experiment though that would be helpful. Go do a WOT pull and note the AFR. Then pull your negative battery terminal for ~30 seconds to clear your learned data off your ecu. Then go do another WOT pull. If the AFR's are significantly different, then that would indicate the LTFT's are messing with your tune.